Former intelligence contractor Edward Snowden says the UK Government Communications Headquarters (GCHQ) has the ability to take over users’ smartphones using a series of tools named after cartoon characters the Smurfs.

Snowden identified several of the tools which he alleges are used by GCHQ and what they do.

‘Dreamy Smurf’ can apparently turn a handset on and off, while ‘Tracker Smurf’ allows more precise geo-location than can be obtained from triangulating cell phone towers and ‘Nosey Smurf’ can remotely access user microphones and eavesdrop on entire conversations.

Other tools can be used to photograph users and monitor calls, texts, contacts, places visited and wireless networks associated with the phone.

Snowden said that GCHQ can access handsets by sending “a specially crafted message” which is hidden from users once it reaches the phone.

“You paid for it [the phone] but whoever controls the software owns the phone,” he said.

Snowden said that despite the fact that the technology was developed in response to increased use of smartphones for serious crimes such as paedophilia and to facilitate communications between terrorists, the agency still collects “mass data” to do so.

He said that GCHQ “is to all intents and purposes a subsidiary of the NSA”, and that the British agency takes its lead on tasks and directions from its US counterpart.

Snowden said that the information he shares is in the public interest because surveillance is carried out “without our knowledge, without our consent and without any sort of democratic participation”.

GCHQ has said that all activities are “authorised, necessary and proportionate”, and refused to confirm if Snowden’s ‘Smurf Suite’ allegations are true or not.